UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Na 8Al 6Si 6O 24Cl 2Michael OâDonoghue , Gems, Sixth Edition (2006)
PbSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references